Certain benzenoid hydrocarbons are known to be potent carcinogens. Their arene oxide forms and further hydroxylation products are now believed to be the causative agents of carcinogenicity. In another connection, special interest has been accorded several types of terpenoid di- and triepoxides because of their potent cytotoxic properties, and anti-leukemic activity in particular. This proposal describes the synthesis of new types of nonbenzenoid polyunsaturated systems which are expected to have heightened reactivity and accordingly be more easily subject to in vivo epoxidation and hydroxylation. The mono- and polyepoxides of these molecules are to be prepared for evaluation as anticancer agents. The hydrocarbons will be screened for their carcinogenesis potential. In part, the synthesis of the epoxides will require the utilization of singlet oxygen as a reagent. Preliminary results indicate considerable promise in the stereoelectronic control of this reagent, a phenomenon which may have widespread importance in many areas of biology and environmental chemistry. Finally, 1O2 will be put to use in organic synthesis. Chirality transfer from silicon to carbon is planned, as is the preparation of dolatriol, a powerfully cytotoxic diterpene alcohol.